Introduction to Models

Online, Self-Paced

Course Description

Rails is a web application framework that provides default structures for a database, a web service, and web pages. Rails lets you write code by favoring convention over configuration. In this course, you will learn how to work with the ActiveRecord, perform validations, and work with virtual models including model callbacks.

Learning Objectives

ActiveRecord Basics

start the course

describe the basics of how ActiveRecord works

use has_one, has_many, and belongs_to associations

use the :through association

make one class belongs_to more than one type of another class

use virtual attributes

persist data into multiple models

describe Hstore and how it is used

Validation

perform model validation

use conditional validation

use custom validators in models

use custom validators in classes

compare using the errors[ ] with the invalid? method

recall what methods do not invoke validations

protect against attacks by controlling mass-assignment attributes

Advanced ActiveRecord

use .where and .find

execute a raw SQL query

compare the .select and .pluck methods

use different finder methods to retrieve objects from the database

Scopes

define and chain query criteria

chain scopes with lambdas

Eager Loading

load all the specified associations with the minimum number of queries

Virtual Models

use active model

ActiveRecord Concerns

recall how to use modules to share functionality between disparate model classes

Model Callbacks

use conditional callbacks

use transaction callbacks

Practice: ActiveRecord

use ActiveRecord to model data

Framework Connections

The materials within this course focus on the Knowledge Skills and Abilities (KSAs) identified within the Specialty Areas listed below. Click to view Specialty Area details within the interactive National Cybersecurity Workforce Framework.